The General Clinical Research Center of the University of Rochester provides the basic needs for most of the clinical investigation done in this institution. Twenty-six investigators participated in over 50 active protocols in the center during the past year. Projects undergoing study at present and during the next year include 1) metabolic changes in patients with cancer, 2) differential diagnostic studies of patients with possible hyperparathyroidism, 3) hypercalcuric effect of carbohydrate administration, 4) total body water and potassium in diabetes mellitus, 5) release of pituitary and pancreatic hormones, 6) effect of malabsorption inducing agents in patients with obesity after intestinal by-pass surgery, 7) urinary output of fluoride and hydroxyproline as indicators of bone metabolism, 8) mechanism of lipolysis in fasting, 9) metabolic abnormalities in neuromuscular disease, 10) antidiuretic hormone in hypertension, 11) study of copper metabolism and use of chelating agents in liver disease, 12) changes in amino acid blood levels with change in oral and parenteral intake, 13) muscimol therapy of Huntington's disease, 14) catabolism of IgG subclasses in selected hypogammaglobulinemic patients, and 15) pathogenetic mechanisms in essential hypertension.